Defeating Eobard Thawne
by EyesOnly-with-wifi
Summary: With Team Flash closer than ever to the man in yellow, Iris has an idea that might just turn the tables in their favour. AU 1x23, killervibe origin story
1. Chapter 1

"You can't defeat me," said Eobard Thawne, the reverse flash. He was stood outside S.T.A.R. labs and the team were watching him over the CCTV. Barry stepped away from the desk and Caitlin knew what he was thinking instantly.

"Barry, wait," she protested but he was already nothing but a gust of wind and a flash of yellow lightning.

"He's not going to…" Joe began to ask, but they already knew the answer. Of course he was. Brave yet reckless Barry Allen.

He appeared on their computer screen, panting and furious. "You killed my mother!" he shouted, emotion raw in his voice.

"I know," sighed Eobard, as if he had heard it a thousand times before, which to be fair, he had. "Yet you still can't catch me."

He vanished, leaving a trail of red lightning and Barry let out an anguished cry and gave chase.

Driven by the need for revenge, justice and closure that had dominated nearly 15 years of his life and shaped his every decision, Barry ran. He tried to ignore the number of times that traitor had made him faster. That didn't matter now. He ran for his mother, he ran for his father, but not just them. He ran for Caitlin and Cisco, Joe and Iris, Felicity and Oliver, Diggle and Lyla, Ray, Roy, Eddie, Captain Singh, everybody who had ever mattered to him because he had to protect them. And he could, if he could just stop the man in yellow. Yet he was always one step ahead.

When Barry set off running Iris took her father's hand. All those months Barry had been in a coma she had been worried about losing him, but it was nothing like this. That worry had been parasitic, gnawing away at her. This was sharp, strong and she wasn't sure she could stand. Iris collapsed into the chair Caitlin had just vacated for her.

"Barry's gonna be fine," said Joe, putting a hand on his daughter's shoulder. She spun her chair around and buried her face in her father's chest, letting the tears flow. She didn't know how long they stayed like that, but eventually Cisco spoke up.

"Man…" he breathed. The majority of windows in Central City had been shattered. It was all over the news.

"They did that?" Iris sniffed.

Caitlin nodded, "according to the footage."

A huge gust of wind nearly knocked them all over and sent all manner of things flying. Barry lay on the floor panting. "I didn't…catch him," he wheezed.

Iris ran over to him and placed a hand on his cheek. "It's okay. Just be thankful you're alive," she whispered. Barry nodded and took her free hand in his.

"So you both got your speed from the Accelerator explosion and other people got powers too?" asked Iris. Barry nodded. "But dad, Eddie, Caitlin, Cisco and I didn't get powers?"

"What are you saying?" asked Caitlin.

"If we re-explode the Accelerator to give ourselves powers we might be in with a better chance of defeating Wells," suggested Iris. She knew it was crazy but at the same time she wanted to catch the man who had killed Mrs Allen and completely ruined Barry's life.

Caitlin looked at Joe, the resident authority figure, in disbelief. "After the devastation the first explosion caused you can't honestly think a second one would be a good idea?" she asked in her 'spectacularly angry way'.

"Surely there's a way you can control the explosion if you know it's going to happen?" asked Iris.

Cisco couldn't believe he was saying it, but "there is a way."

Joe looked at Barry who was staring at the ground. "Bar?"

Barry didn't look up, "yeah, it could work." He shrugged and left the pipeline, dragging his feet and hands in his pockets.

After a quick apologetic glance at the others Joe followed him out. "What's wrong?" he asked.

Barry spun round and looked his foster dad in the eye. "If we do this, how many people will die? The entire city could be flattened because of us."

"Don't you trust Cisco? He knows what he's doing."

"No, it's not Cisco. It's the Accelerator. We trusted Dr – Eobard and he betrayed us. This entire building is a lie," Barry shouted, clasping his hands behind his head.

Caitlin knocked quietly on the wall. "Sorry to interrupt but this sounds like it ought to be private and we can all hear you. Also, Iris wants to speak to you, Barry."

He nodded at Caitlin. Joe raised his eyebrows.

"Two days, Joe, to see what they come up with."

"Look, Barry, I'm not an idiot. I know this isn't the best idea in the world but I honestly don't see another way we can actually defeat him!" Iris argued.

"Are you saying I can't defeat him?"

"I'm saying you've tried and look where that got you."

Barry hated to admit it, but she was right. He couldn't stop the man in yellow, he didn't even know who he was when he was right in front of him. He needed a team. Eobard had taught him that much.

"Alright," he said, rubbing his face, "if we are ready in two days, we'll do it."

"Thank you," whispered Iris as they hugged.

The next day, preparations began. Iris, Eddie and Joe went to work, Barry was sent to Starling City to keep Team Arrow in the loop and Caitlin and Cisco began work on the Accelerator.

"How's it going?" asked Caitlin.

"Alright," Cisco replied, frowning at a piece of circuitry. "If I don't short out the super-capacitors we should be ready to go tomorrow."

"Great," she smiled. "I brought you a Slushy." She passed him his and took a sip of her own.

"Thanks."

"Can I do anything to help?"

Cisco thought for a second. "I'm going to double-check the current in a second, so you can go and monitor the cameras in case there's an emergency and we need to call Barry."

As Caitlin left he took one last glance and turned it on. Slowly, it lit up and the numbers increased on the Ammeter. And kept increasing until sparks flew off the components. Not good, he thought. Then they caught fire. "CAITLIN!"

 **AN - will eventually be a meta-human origin story for Killer Frost, Vibe and a few others. Let me know what you think, and if you have any suggestions.**


	2. Chapter 2

Caitlin's POV

I hear Cisco shout somewhere in the distance and feel the dry heat of fire coming towards me. Yet instead of feeling hot I feel cold. So cold. The Slushy in my hand is making it worse. I realise and drop it. A blue puddle forms around my feet, and I notice the room feels unfamiliar. It resembles some sort of intensive care chamber. Probably another of Eobard's secret projects.

I'd never been one to experiment with science without calculating the risks first, and something was clearly wrong with this room. No emergency exit, no windows, not even a thermostat. I'm freezing now, and remember that the best way to keep warm is to exercise. I attempt to move but my frozen limbs don't respond and I stumble against the wall. I slide down it, my shoulder hitting a button and curl up on the floor, involuntarily shuddering every few seconds. The button triggers some sort of alarm, and glass doors slide down trapping me. Air vents I had not previously noticed on the ceiling suck out whatever warmth remained. My lungs feel as though they are about to freeze solid and crystals form in the air every time I exhale. Finally I accept this is the end and rest my head on the ground.

That's when everything changes. I open my eyes and the room looks sharper than before. The agonizing cold has gone, leaving a sharp drive for heat. The blood has frozen in my veins and my hair changes too. All the heat is sucked out of it. I need more. I place my hands on the glass panel separating me from the world and pull. It gets weaker and weaker until it shatters. Shards rain down around me as I walk towards the heat.

I step directly into the fire and the heat flows through me. It's like a breath of fresh air. It reinvigorates me but only for a second before it goes out. I step forwards, searching for more, then I see it. A human. I can feel the heat radiating off it and reach out, when it speaks.

"Caitlin?"

Instinct takes over and I feel a name spring to my lips. My voice sounds unfamiliar and hollow. "Cisco?"

 **AN: Updates should hopefully be much faster from now on (and longer). Thank you to everyone who favourited and followed :)**


	3. Chapter 3

Suddenly, I saw it. What had previously been fragments of images or long-forgotten dreams clicked into focus. But I recognised none of it. Conversations Caitlin and I never had, things Barry never did. And Dr Wells…Dr Wells killing me. I feel another scream tearing out of my throat, but instead of sound, vibrations come out and shatter the console I was working on. The console! The Accelerator exploded. Does that make me a meta-human? Probably. Scary thought, like something out of a movie. But I don't have time to think about it.

For the first time, I notice the fire. Is it really there, or is it another one of those memories? The fire goes out, revealing a familiar figure shrouded in smoke. She steps towards me. "Caitlin?"

She looks like my best friend but her hair is so pale it's almost white and much thicker than before. Her eyes are a sharp blue and stare at me hungrily. When I speak she stops, then says my name. her voice is cold and empty. "It's me, Caitlin," I say, taking a step towards her. She moves away like a frightened animal.

"Don't come near me," she says in that terrible voice.

"Guys?" Barry asks over the intercom. "Everything ok?"

"No problems," I reply without taking my eyes off Caitlin. "Everything is under control."

Barry hangs up and Caitlin seems more relaxed and like herself. "I'm…so…hungry," she whispers.

"You want food?" I pull a candy bar out of my pocket and offer it to her.

"Not food. Heat."

I turn up the thermostat but it doesn't seem to make much of a difference. As I do it, I realise I am now the one in the position of leadership. I'd never had to before, Caitlin or Dr Wells had always been the one who took charge. I helped from behind the scenes and provided enthusiasm. I'd never been one for being in the spotlight.

"Heat," muttered Caitlin. Then an idea came to me, and I picked up the phone.

"Hello?"

"How fast can you get to S.T.A.R. labs? We have a situation," I explained. They hung up, then out of the blue the memory of Dr Wells killing me returns and I hear something smash in the distance.


	4. Chapter 4

Ronnie's POV

I jump a mile high when the phone rings. "Hello?"

Cisco's voice replies, sounding tense and worried. "How fast can you get to S.T.A.R. labs? We have a situation."

Caitlin! I hang up quickly and run to fond Professor Stein. "Professor!" I shout when I found his office empty.

"What's the emergency, Ronald?" he asks calmly, returning with a stack of papers.

"S.T.A.R. labs needs us, they have a 'situation'," I say. we merge and fly to the lab, but the sight that greets us is worse than anything we could have imagined.

Caitlin, my Cait, lay on the floor, her hair white and her eyes hungry and pale blue, and her skin. Oh God, her skin freezing to touch.

"Ronnie," mutters Prof Stein, looking faintly sick. Cisco was sat in the middle of a pile of wreckage, staring off into the distance.

"What happened?" I ask, looking round in horror.

Prof Stein kneels down and gently prods Cisco. The young engineer snaps to attention, breathing heavily. "What happened?" Stein asks gently.

"Dr Wells killed me!" Cisco sobs. "Wait, no. that didn't happen. The Accelerator 2.0 blew up. Caitlin and I are meta-humans." He turns to look at her. "She needs heat. That's why I called you."

Stein and I merge, and take Caitlin's hand. I feel a strange pulling sensation, as if she is taking something out of me. Slowly, she sits up and her hair and eyes return to their normal colour. She loses the hungry look and smiles at me. "Ronnie," she whispers. Joy rushes through me like adrenalin.

"It's me Cait," I say.

"Me too," adds Stein.

Caitlin laughs. Cisco smiles, but he still looks haunted. "We can't tell anybody. At least, not until we've defeated Eobard Thawne," he says, looking down.

"WHAT?" I shout. "Look at Cait, look at you. Actually, what happened to you?"

"This." Cisco lets out an inhuman cry and smashes what remained of furniture. "Also, I appear to be able to remember things that haven't happened."

"Possible alternate timelines," says Stein.

Caitlin shivers, and I set my hands on fire to be able to give her more warmth. She smiles gratefully. "Anyway," she says. "Barry will be on his way now. We'd better clean this place up."

Caitlin's POV

We cleared everything up surprisingly quickly, and before we knew it Barry was back.

"How's the Accelerator going?" he asks.

"It's ready to go," lies Cisco, pulling it off surprisingly well.

"Great. Any news on Eobard?" Barry asks Firestorm. They were still merged to give me enough heat to look human.

"Actually yes," replies Stein. "We traced his phone to a warehouse near CCPD, but there's no telling if his phone is actually with him."

Barry nods. "Caitlin, can you work on traffic cams and the blah nearby?"

"On it," I say, slowly letting go of Ronnie's hand and beginning to type. The cold gets worse immediately, and this time there is pain as well. I focus on the task in front of me, until I see the tips of my hair turning white, and instead decide to focus on looking myself. I think happy thoughts: Cisco making me laugh, Ronnie proposing to me, helping Barry take down bad guys. My hair returns to its normal colour, but I just can't do this anymore. Dr Caitlin Snow no longer exists. I am something else now, something else entirely.

"How's it going?" Cisco asks, coming over holding his tablet.

"Good," I whisper, not meeting his eyes.

"I can tell when you're not ok," he points out.

"Well, I doubt there's anything you can do about it," I snarl. He places a hand over mine and I flinch away instantly. "Don't touch me."

"Look, I'm finding this just as hard as you," he says.

"Somehow I doubt that." My hair starts turning white again, but I'm out of ideas. Right, traffic cams. I rewind the footage until I see Eobard Thawne. I still can't get used to the sight of him without the wheelchair and glasses.

Barry comes back holding his phone. "I just spoke to Joe, he says nobody at the CCPD has seen him, so maybe the phone was just a red herring."

"It's not," I say, pointing to the screen in front of me. "He was definitely there." Barry leans over me to get a closer look. I can feel the heat coming off him and have to restrain myself.

"Can you-" begins Barry but I stand up, cutting him off.

"I'm sorry," I announce. "I can't do this anymore." I let go, and I feel myself turning into the creature I was before. I leave the room and follow my instincts. Ignoring the stares I get on the street, I go to the warehouse. As I knew he would be, Eobard Thawne is there. I look him dead in the eye, ignoring the surprise and confusion.

"The name's Frost. Killer Frost."


	5. Chapter 5

**AN- this chapter is a bit confusing, sorry. There are a few time-skips but everything is in chronological order. I just wanted to kind of set things up for where the story goes next. The next chapter will be more exciting :)**

The next day

Ronnie hung up his phone. "Cait is fine, she just wasn't feeling so good. Cisco is staying at home as well, they think it was something to do with the Accelerator 2.0."

Barry nodded. "Yeah, ok. I'll call Joe and see if he can get us a task force to storm the warehouse."

Joe answered with a worried hello. "Is everything ok?" asked Barry.

"Look, now isn't a good time. I'll call you back later." Joe hung up before Barry could reply.

"That was weird." Barry frowned at his phone. "We should go to the CCPD, Joe and Iris might be in danger."

Prof Stein shook his head. "That's not so wise."

Barry clasped his hands behind his head. "No, I'm going. This man killed my mom! I'm going to do whatever I can to stop him."

Ronnie nodded. "We're coming with."

At the CCPD

"Joe?" asked Barry. Joe jumped a mile high.

"Don't sneak up on me like that, Bear." He sighed. "I might as well tell you now."

Barry's heart rate increased rapidly. "Tell me what?"

Joe winced. "The Accelerator 2.0, it went off, and well…we were all effected."

"What?! Why didn't you tell me?!" Barry shouted.

"Duh, I just did. We're not entirely sure but I appear to be able to do this." Joe picked up a paperweight and threw it. It sailed across the room in a super-powered arc. "Eddie has X-ray vision and Iris – who is still at Picture News – can read minds. She called me earlier to say. Eddie is still at hospital, he broke his leg."

Ronnie sighed and helped himself to a slice of pizza from Joe's desk, ignoring his protests. "Well," he struggled to say around the pizza, "Eobard will have certainly enjoyed that. Now that we're super-powered-up we might as well go get him. It's now or never."

Outside the warehouse

"They're inside," Iris whispered. "They don't know we're here." Joe picked up a nearby trash can and threw it at the door. The door shattered instantly and the team entered in formation. Firestorm's hands lit up and Iris did a quick scan of the room to see if anybody was planning to attack. They were too surprised.

Eobard Thawne walked into the main room applauding. "I have to say, I'm surprised such a motley crew could even find my warehouse."

"Looks like we're a lot tougher than you think," said Barry.

Eobard shrugged. "What can I say, sometimes you need a little secret weapon. Killer!" he shouted. A person who looked like Caitlin entered, but there was something different about her. Something wild and feral. "You may feed on these insolent fools. Start with the fast one."

Caitlin, or what had been Caitlin, stepped towards Barry and placed her cold hands on his chest. She leant forwards like she was going to kiss him, and placed her lips just below his ear. "Back entrance, tomorrow," she whispered. Then the world around Barry shook as all the heat and life force drained out of him. Caitlin stepped back, and for just a second some of her former colour returned. "That's enough," she said, her voice chilling them to the bone. "Don't bother me with these people anymore." She left again, showing no emotion.

Eobard laughed. "So, you have me. What are you going to do? Throw me in the Pipeline?"

Iris did a quick scan of Eobard, and he showed no signs of attack. "He just wants to talk," she said quietly to her dad. But Joe picked up the same trash can from earlier and threw it at Eobard. But the speedster moved out of the way with practiced ease.

"Did you think you could catch me with the same trick twice? Come on Barry, you can do better."


	6. Chapter 6

Still reeling from Caitlin stealing his heat, Barry mustered all the strength and speed he could and rugby tackled Eobard to the ground. Once he had him, Joe held Eobard down using his super strength.

"Barry," came Cisco's voice in his suits speakers.

"Cisco, are you at S.T.A.R. labs?" asked Barry.

"Yeah. Listen, you need to get out of there now. No time to explain, just go."

"Wait-" but Cisco had hung up. "Guys, we need to go."

They didn't question his orders, and piled into the mobile lab van.

"You gonna tell us what came over you back there?" asked Joe.

"Cisco said we had to go."

…..

Back at S.T.A.R. labs, Cisco was explaining why he'd told them to leave. "Since the explosion, I've been able to see things. Futures and pasts that haven't happened. In one where you stayed to fight Eobard, I don't even want to say what happened…"

The room fell silent. Nobody dared break it until Eddie entered, his previously broken leg completely fine. "Turns out I got healing powers as well as X-ray vision. This is all pretty cool."

"Ok," Iris said, sitting down at the computer. "Barry, what did Caitlin say to you?"

"How do you know she…" Iris raised her eyebrows. "Ok. She said to meet us at the back entrance tomorrow."

"You're not gonna go, right?" asked Joe.

Barry glanced at Iris, who spun in her chair. Running a hand through his hair, he sighed. "Yes. I have to go. Caitlin was our friend, is our friend!"

Ronnie, who had been stood in silence since they got back, spoke up. "I'm going too."

"Me too," said Prof Stein. "Dr Snow is no lost cause."

…..

It was dark when they finally arrived once more outside the warehouse. Barry, Ronnie, Prof Stein and Cisco were there, with Iris and Joe in S.T.A.R. labs.

"Are you sure this is a good idea? Shouldn't we have, like, Nerf guns or something?" asked Cisco.

Nobody had a chance to reply, as the ground beneath them froze and Killer Frost stepped out of the shadows. She formed a shield of ice around them. "We can talk freely, nobody can hear us through the ice.

"So, here's the deal. I'm not entirely sure what happened with Accelerator 2.0, but my powers are something like Farooq Gibron or Blackout's. I had to make Eobard think I was on his side, and to do that I had to steal your heat, Barry. Since your cells are in a constant state of regeneration, I knew you were the only one who could take it."

Ronnie took a shaky breath. "Do you have a plan, Cait?"

She took a step towards him. "Not as of yet, but hopefully I'll be able to provide you with some inside info. Whatever you do, don't give up." The barrier of ice started to melt. "I'll be in touch."

Caitlin slid back inside the building and Team Flash headed back to S.T.A.R. labs. Cisco was still trying to digest all that had happened when he felt the world shift.

 _Cisco was stood in the bunker below S.T.A.R. labs, and Eobard Thawne was there. No wheelchair, no glasses. Walking towards Cisco. He lifted up his hand and vibrated it. Cisco could just see flashes of red lightning. Then he shoved his hand into Cisco's chest and the pain was like nothing he'd ever felt._

"Cisco, what happened?" asked Barry. He was on the floor and Barry was knelt next to him. Cisco brought a hand up to his chest in confusion.

"Dr Wells, no Eobard…"

"It's ok," said Barry. "Hold on." He answered the phone. "It's Caitlin. She says Eobard's speed just cut out. Let's do this."

 **AN - sorry for the wait. And thank you so much to Guest for the comment, I'm glad you are enjoying it.**


	7. Chapter 7

"Not now," groaned Eobard, as he stuttered to a halt and crashed into the table. The red lightning behind him flickered and died. From outside Killer Frost watched closely, then pulled out her phone.

"Barry," she whispered. "Eobard's speed just cut out. It's now or never."

Killer snuck round the back and ran up to her room upstairs before Eobard could notice she was gone. Within seconds, a yellow flash was visible just outside the window. Behind him were Joe, Eddie, Iris and Cisco. It had begun.

The door hadn't been fixed since Joe had last smashed it, so they walked straight in, in perfect formation.

"We meet again," said Eobard, his voice betraying no emotion.

"We do. You killed my mother!" shouted Barry.

"I know," sighed Eobard. "And now you're here for revenge. Well, come and get me!"

Iris came up by Barry's elbow. "He's not bluffing. I can't make anything out," she whispered, confused.

"We got this," said Barry, with more confidence than all of Team Flash felt put together.

Eobard moved towards Barry and lifted his hand, vibrating it. "Now for the fun part."

Barry dodged out of the way, and pushed over the table. Joe picked it up and swung at Eobard, but he did a commando roll and pulled Iris's legs out from under her. She screamed, but recovered herself quickly.

Eobard ran over to a nearby cabinet and pulled out a gun, locking and loading it trained on Barry. Before any of them could register what had happened, he pulled the trigger. Time slowed for all of them as the bullet sped towards the Flash. Iris picked up something sinister from Eobard's mind, just in time for her to let out an unintelligible cry. Eddie clocked what was going on before Barry did, and threw himself in front of the gun.

"EDDIE!" screamed Iris, running over to him. The cop said nothing, but thought something so hard Iris could clearly hear it. 'Super healing, remember. I'll be fine.'

 _I love you_ , thought Iris. And, judging from the expression on Eddie's face he had heard it. _Wait, can you hear me?_ thought Iris.

Eddie nodded.

 _We can use this to our advantage_ , she thought. Closing her eyes, Iris thought as clearly as she could about her friends. _Barry, Dad, Eddie, Cisco and Caitlin._

 _Can you hear me?_ she asked them.

The replies all came at once. _Yes._

Iris assessed the room. Barry and Eobard were fighting, Joe was attempting to help Barry and Caitlin and Cisco were nowhere to be seen.

 _I have a plan_ , thought Iris. _Listen carefully._

…..

Meanwhile, upstairs Cisco had slipped upstairs and was speaking to Caitlin.

"So, saying we somehow take down Eobard Thawne, what will we do with him?" asked Caitlin.

"Arrest him," said Cisco like it was the most obvious thing in the world. "It's not quantum physics you know."

"I would probably find that easier," sighed Caitlin. "We have no grounds for arresting him! He hasn't confessed to Nora Allen's murder, he hasn't actually killed anyone we know about and last time I checked setting up shop in an abandoned warehouse isn't illegal."

"Whoa, that's weird," said Cisco, putting a hand up to his head.

…..

Barry prepared himself for what was about to come. Out of the corner of his eye he saw Cisco sneak into the main room, squat down and place his hands on the ground. Suddenly, the entire room shook and Eobard, being the only one not expecting it, was rattled. He stumbled against the wall, and Caitlin descended the staircase with such a force of will that the whole room felt compelled to look at her. She raised an arm and encased Eobard Thawne in a cocoon of ice.

"Killer, what- you're on my-"

"MY NAME IS CAITLIN SNOW!" she said, her voice echoing throughout the entire warehouse.

Something in Eobard just gave up. He had finally been overpowered by the people he had brought up from nothing. All the work he had put in, making sure Barry would become the Flash was for nothing.

An hour later

The pipeline seal slid down and Barry looked Eobard in the eye until he could no longer see him.

"It is over," said Barry Allen.

THE END

 **AN - so here it is, the final chapter. Thanks to everyone who read, reviewed, faved and followed.**


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